A valve opening and closing timing control apparatus such as mentioned above is disclosed, for example, in Patent document 1. In the valve opening and closing timing control apparatus, in order to allow an internal combustion engine to start even in a case where a failure occurs, a phase of an electric valve opening and closing timing control apparatus provided at an intake valve is controlled to a most retarded angle side while a phase of a valve opening and closing timing control apparatus provided at an exhaust valve is controlled to a most advanced angle side.
In the internal combustion engine, in a case where the electric valve opening and closing timing control apparatus fails and a driving motor malfunctions, a rotation torque of a planetary gear in a planetary gear mechanism provided at the valve opening and closing timing control apparatus disappears. As a result, a ring gear operating in conjunction with a crankshaft of the internal combustion engine and a sun gear connected to a camshaft are inhibited from rotating in the same rotational period. Because the camshaft receives resistance by a spring provided at the intake valve, the camshaft to which a driving force is not transmitted is retarded relative to the ring gear and is arranged at a most retarded angle position at a mechanical stopper position.
In the internal combustion engine, even in a case where the camshaft is specified at a most retarded angle phase, the most retarded angle phase serves as an appropriate position for the start of the internal combustion engine. Thus, even when the electric valve opening and closing timing control apparatus malfunctions, the start of the internal combustion engine is achievable.